The research program examines the mechanisms by which GI hormones and neurotransmitters control the electrical and mechanical activity of smooth muscle of the antrum of humans, dogs and cats. In vitro methods include the intracellular and double sucrose gap techniques. Major areas of interest include: (a) the ionic basis of the pacemaker potential, (b) the influence of the intramural nervous system on the pacemaker potential and (c) the site and mechanism of action of GI hormones and neurotransmitters.